Method and apparatus for transmitting and receiving data

ABSTRACT

The present disclosure presents a method for a first receiver in a first communication link, the first communication link sharing a communication channel with a second communication link in a wireless network, the first communication link corresponding to a first set of beam directions, the second communication link corresponding to a second set of beam directions, and the method comprises determining whether a communication quality satisfies a predefined criterion; and selecting a first beam direction from the first set of beam directions in response to determining the communication quality satisfying the predefined criterion. The present disclosure also presents a further method for a second transmitter and the further method comprising receiving a beam direction selection signaling and selecting a second beam direction from the second set of beam directions in the second communication link. The first receiver and the second transmitter in respective communication links are also disclosed.

This application is a continuation of U.S. application Ser. No.16/488,192, filed Aug. 22, 2019, which is a 35 U.S.C. § 371 nationalphase filing of International Application No. PCT/CN2017/083614, filedMay 9, 2017, the disclosures of which are incorporated herein byreference in their entireties.

TECHNICAL FIELD

The present disclosure is generally directed to methods for transmittingand receiving data in a first communication link and a secondcommunication link in a shared band in a wireless network andtransmitter and receiver apparatuses thereof.

BACKGROUND

In order to meet an increasing demand for higher overall networkcapability and higher end-user data rate, the next generation ofwireless communication system, such as the fifth generation (5G)communication system, is expected to be operating in unlicensed sharedbands, especially for enterprise solutions. Thus coexistence support oftwo or more communication links is needed for the contention basedaccess in order to enable spectrum sharing between different operatorsor other communication systems.

Listen-before-talk (LBT) mechanism is a flexible way to achieve thiscoexistence support between different communication systems inunlicensed shared band, in which a communication node intending totransmit data first performs a channel sensing, such as in a clearchannel assessment (CCA) procedure, and checks whether the channel isavailable or not. The communication node will transmit data when itdetermines that the shared channel is available, otherwise thecommunication node will defer its transmission for a certain perioduntil the channel is deemed to be free. LBT relies on listening attransmitter side to determine if there will be interference at thereceiver side and thus there may be a large difference between sensedpower at the transmitter side and the actual interference power at thereceiver side especially in high gain beamforming scenarios, which mayresult in severe problems. For example, the transmitter may be unable tolisten to the potential interferer resulting into packet collision,i.e., interference at the receiver side.

For communication throughput, the different communication links sharethe unlicensed band in a time division way, which means the throughputof each communication link is severely degraded compared to with atraditional isolation deployment. Moreover, there may be some lowinterference application scenarios, and thus, the channel sensingprocedure performed in a transmitting node before the actual datatransmission may waste transmission resource, leading to lower spectrumefficiency.

SUMMARY

It is an object of the present disclosure to resolve or alleviate atleast one of the problems mentioned above. It is assumed that there areat least two communication links sharing an unlicensed band in awireless network. A transmitter in a communication link will transmitits data without performing a channel sensing procedure first, and thereceiver will try to solve the potential interference from anothercommunication link through a beam direction switching procedure, therebyimproving the overall spectrum efficiency for the wireless network. Forsimplicity, those two links sharing the unlicensed band are describedthereinafter.

According to one aspect of the disclosure, there is provided a methodfor a first receiver receiving data from a first transmitter in a firstcommunication link, the first communication link sharing a communicationchannel with a second communication link between a second transmitterand a second receiver in a wireless network, the first communicationlink corresponding to a first set of beam directions, the methodcomprises a step of receiving data from the first transmitter in a firstactive beam direction in the first communication link, in presence ofinterference from the second communication link, a step of determiningwhether a communication quality satisfies a predefined criterion, and astep of selecting a first beam direction from the first set of beamdirections in response to determining the communication qualitysatisfying the predefined criterion.

According to a further aspect of the disclosure, there is provided afurther method for the first receiver in the first communication link,in which the step of determining whether a communication qualitysatisfies a predefined criterion comprises a step of decoding the datareceived from the first transmitter in the first communication link; anda step of determining whether the data is successfully decoded, and thestep of selecting a first beam direction from the first set of beamdirections comprises a step of selecting a first beam direction from thefirst set of beam directions in response to determining the data is notsuccessfully decoded.

According to a further aspect of the disclosure, there is provided afurther method for the first receiver in the first communication link,in which the step of determining whether a communication qualitysatisfies a predefined criterion comprises a step of measuring aninterference from the second communication link in the first active beamdirection, and a step of determining whether the interference is higherthan a predefined active-beam interference level, and the step ofselecting a first beam direction from the first set of beam directionscomprises a step of electing a first beam direction from the first setof beam directions in response to determining the interference levelbeing higher than the predefined active-beam interference level.

According to a further aspect of the disclosure, there is provided afurther method for the first receiver in the first communication link,in which the step of selecting a first beam direction from the first setof beam directions comprises a step of measuring an interference fromthe second communication link in each of the first set of beamdirections, and a step of selecting a first beam direction with aninterference measurement value being lower than an interferencethreshold.

According to a further aspect of the disclosure, there is provided afurther method for the first receiver in the first communication link,in which the second communication link corresponding to a second set ofbeam directions and the method further comprises a step of informing thefirst transmitter to continue transmitting data in the first active beamdirection in the first communication link, in response to the selectedfirst beam direction being the first active beam direction.

According to a further aspect of the disclosure, there is provided afurther method for the first receiver in the first communication link,in which the second communication link corresponding to a second set ofbeam directions and the method further comprises a step of sending abeam direction selection signaling to the second transmitter of thesecond communication link in response to the selected first beamdirection being the first active beam direction, and the signalingindicating the second transmitter to select a second beam direction fromthe second set of beam direction in the second communication link.

According to another aspect of the disclosure, there is provided amethod for a second transmitter transmitting data to a second receiverin a second communication link, the second communication link sharing acommunication channel with a first communication link between a firsttransmitter and a first receiver in a wireless network, the secondcommunication link corresponding to a second set of beam directions, themethod comprises a step of receiving a beam direction selectionsignaling from the first receiver, wherein the signaling indicating thesecond transmitter to select a second beam direction from the second setof beam direction, and a step of selecting a second beam direction otherthan the second active beam direction from the second set of beamdirections in the second communication link.

According to a further aspect of the disclosure, there is provided afurther method for the second transmitter in the second communicationlink, in which the step of selecting the second beam direction from thesecond set of beam directions comprises a step of selecting the secondbeam direction based on a space departure of each of second set of beamdirections with respect to the second active beam direction.

According to a further aspect of the disclosure, there is provided afurther method for the second transmitter in the second communicationlink, in which the step of selecting the second beam direction from thesecond set of beam directions further comprises a step of selecting thesecond beam direction based on a geometric position of the firstreceiver, wherein the geometric position of the first receiver isconveyed in the beam direction selection signaling.

According to a further aspect of the disclosure, there is provided afurther method for the second transmitter in the second communicationlink, in which the step of selecting the second beam direction from thesecond set of beam directions further comprises a step of selecting thesecond beam direction based on a mapping between each of the second setof beam directions and an interference level.

According to a further aspect of the disclosure, there is provided afurther method for the second transmitter in the second communicationlink, in which the method further comprises a step of informing thesecond receiver with the selected second beam direction and a step oftransmitting data to the second receiver in the selected second beamdirection in the second communication link.

According to a further aspect of the disclosure, there is provided afurther method for the second transmitter in the second communicationlink, in which the method further comprises a step of in response toreceiving the beam direction selection signaling from the first receiverfor a preset number of times, suspending transmitting data to the secondreceiver in the second communication link for a preset period.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary features of the present invention are set forth in theappended claims. However, the present invention, its implementationmode, other objectives, features and advantages will be betterunderstood through reading the following detailed description on theexemplary embodiments with reference to the accompanying drawings, wherein the drawings:

FIG. 1 illustrates an exemplary flow diagram for a method in a firstreceiver in a first communication link in a wireless network accordingto one or more embodiments of the invention;

FIG. 2 shows an example for a set of beam directions in a communicationlink between a transmitter and a receiver according to one or moreembodiments of the invention;

FIG. 3 is an exemplary flow diagram of a step of the method of FIG. 1according to one or more embodiments of the invention;

FIG. 4 illustrates an exemplary flow diagram for a method in a secondtransmitter in a second communication link in a wireless networkaccording to one or more embodiments of the invention;

FIG. 5 illustrates an exemplary flow diagram for a process of a firsttransmitter and a first receiver in a first communication link in awireless network according to one or more embodiments of the invention;

FIG. 6 illustrates an exemplary flow diagram for a process of a secondtransmitter and a second receiver in a second communication link in awireless network according to one or more embodiments of the invention;

FIG. 7 schematically shows a block diagram of a first receiver accordingto one or more embodiments of the invention; and

FIG. 8 schematically shows a block diagram of a second transmitteraccording to one or more embodiments of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments herein will be described in detail hereinafter withreference to the accompanying drawings, in which embodiments are shown.These embodiments herein may, however, be embodied in many differentforms and should not be construed as being limited to the embodimentsset forth herein. The elements of the drawings are not necessarily toscale relative to each other. Like numbers refer to like elementsthroughout.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a”, “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprises” “comprising,”“includes” and/or “including” when used herein, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meanings as commonly understood. Itwill be further understood that a term used herein should be interpretedas having a meaning consistent with its meaning in the context of thisspecification and the relevant art and will not be interpreted in anidealized or overly formal sense unless expressly so defined herein.

The present disclosure is described below with reference to blockdiagrams and/or flowchart illustrations of methods, nodes, devicesand/or computer program products according to the present embodiments.It is understood that blocks of the block diagrams and/or flowchartillustrations, and combinations of blocks in the block diagrams and/orflowchart illustrations, may be implemented by computer programinstructions. These computer program instructions may be provided to aprocessor, controller or controlling unit of a general purpose computer,special purpose computer, and/or other programmable data processingapparatus to produce a machine, such that the instructions, whichexecute via the processor of the computer and/or other programmable dataprocessing apparatus, create means for implementing the functions/actsspecified in the block diagrams and/or flowchart block or blocks.

Accordingly, the present technology may be embodied in hardware and/orin software (including firmware, resident software, micro-code, etc.).Furthermore, the present technology may take the form of a computerprogram product on a computer-usable or computer-readable storage mediumhaving computer-usable or computer-readable program code embodied in themedium for use by or in connection with an instruction execution system.In the context of this document, a computer-usable or computer-readablemedium may be any medium that may contain, store, communicate,propagate, or transport the program for use by or in connection with theinstruction execution system, apparatus, or device.

FIG. 1 illustrates an exemplary flow diagram for a method in a firstreceiver in a first communication link in a wireless network accordingto one or more embodiments of the invention. It is assumed there are twocommunication links operating in a shared band in a wireless network.The transmitters and receivers at respective communication links areequipped with multiple antennas to exploit a spatial reuse via variousbeamforming techniques. The first transmitter intends to transmit datato the first receiver in the first communication link, and at the sametime the second transmitter may be transmitting data to the secondreceiver in the second communication link. The first transmitter willnot first perform a channel listening before its transmission to thefirst receiver such as in the LBT mechanism; instead the firsttransmitter may transmit its data even though in presence ofinterference from the second communication link and the first receiverwill solve the potential interference through a beam direction selectionprocedure, leading to higher spectrum efficiency compared with thelegacy LBT protocols. In the present disclosure, the first transmitterfirst transmits the data and then the first receiver will sense theinterference and try to solve the interference by selecting andswitching to another beam direction in the first communication link, andsuch communication protocol may be referred to as listen-after-talk(LAT).

In step 110, the first receiver receives data from the first transmitterin a first active beam direction in the first communication link, inpresence of interference from the second communication link. The termsof beam direction and active beam direction will be explained in detailsas follows. As the first transmitter will not first perform a channelsensing and the second transmitter of the second communication link maybe transmitting in the shared channel, thus the first receiver mayreceive the data in the first communication link in the shared band inpresence of the interference from the second communication link in thewireless network.

A beam direction in a communication link could be represented by aprecoding vector or matrix at a transmitter side and/or a postprocessing vector or matrix at a receiver side, which depend on thespecific beamforming techniques employed for certain applicationscenarios. An active beam direction refers to the beam direction whichis utilized for the current transmission in a communication link. It isassumed that a set of beam directions is available and maintained by thecommunication link. For example, in FIG. 2, there are three beamdirections in a communication link between a transmitter and a receiver,which are equipped with multiple antennas respectively. It should bementioned that the transmitter is illustrated as a base station and thereceiver is illustrated as a mobile user, however, FIG. 2 only serves asa non-limiting example of downlink transmission and the method describedin the present disclosure can be also applied to the uplink transmissionscenarios. This multiple beam configuration is highly likely for indoorscenarios and urban deployments due to fruitful reflections. The beamdirection information should be trained at an initial connectionestablishment process between the transmitter and receiver and then itis stored in both the transmitter and receiver. Furthermore, such beamdirection may be renewed periodically or the beam direction renewal maybe triggered by specific predefined events to guarantee updatedinformation. The beam direction information updating process could bebased on the measurement of certain reference signals, e.g., mobilityreference signals (MRS) in 5G communication systems, so that therobustness could be achieved even in high mobility application scenariofor example. The active beam direction may be switched to another beamdirection for a further transmission, which may be referred to as a newactive beam direction for the further transmission. It should be alsonoted that the method in the present disclosure is not limited toscenarios with only one active beam direction in a communication linkfor data transmission, and one active beam direction is described in thefollowing description only for exemplary illustration. The personskilled in art may appreciate the cases in which multiple active beamdirections are used simultaneously for one transmission, withoutdeparting the spirit and teaching of this disclosure.

In step 120, the first receiver determines whether a communicationquality satisfies a predefined criterion. Interference from the secondcommunication link may exist, and therefore the communication quality inthe active beam direction in the first communication link may bedegraded due to the presence of interference from the secondcommunication link. The communication quality in the first communicationlink is evaluated to determine whether the beam direction switching inthe first communication link should be performed or not. It may bedesirable to exploit different forms of communication quality, whichdepends on the specific system implementations.

In one embodiment of the present invention, the communication qualitycould be measured by the decoding result in the first receiver. Forexample, in sub step 1210, the first receiver may decode the datareceived from the first transmitter in the first communication link; andin sub step 1220, the first receiver determines whether the data issuccessfully decoded, for example, via a Cyclic Redundancy Check (CRC).In this embodiment, an event that communication quality satisfying apredefined criterion refers to that the first receiver determines thatthe data is not successfully decoded due to the interference from thesecond communication link.

In another embodiment of the present invention, the communicationquality may be measured by an interference measurement in the firstactive beam direction. For example, in sub step 1230, the first receivermay measure an interference from the second communication link in theactive beam direction to determine the communication quality. Forexample, the first receiver may have the knowledge of certain referencesignals from the second transmitter, based on which the first receivermay measure the interference from the second communication link. Foranother example, in certain application scenarios, where the onlyinterference source at the first receiver is the second communicationlink, the first receiver may obtain the interference measurement fromthe second communication link according to a total signal power and auseful signal power measured respectively. For still another example,the first receiver may simply take the total interference received atthe first receiver, as the interference from the second communicationlink. In sub step 1240, the first receiver determines whether theinterference is higher than a predefined active-beam interference level.In this embodiment, an event that the communication quality satisfying apredefined criterion refers to that the first receiver determines thatthe interference from the second communication link in the active beamdirection is higher than a predefined active-beam interference level. Insuch cases, the first receiver may select another beam direction inorder to alleviate or mitigate the interference from the secondcommunication link, instead of simply deferring its transmission due tothe interference. It should be appreciated for those skilled in the artthat the communication quality and its corresponding predefinedcriterion could also be a combination of the decoding result, e.g.,success or not and the interference measurement in the active beamdirection. Any modification, variation and change for the specificimplementations of the communication quality may be appreciated by theskilled in the art and thus should fall within the teaching and thescope of the present disclosure.

In step 130, the first receiver selects a first beam direction from thefirst set of beam directions in response to determining thecommunication quality satisfying the predefined criterion. As discussedabove, for one embodiment of the invention, in sub step 1310, the firstreceiver selects a first beam direction from the first set of beamdirections in response to determining the data is not successfullydecoded. For another embodiment of the invention, the first receiver insub step 1320, selects a first beam direction from the first set of beamdirections in response to determining the interference level beinghigher than the predefined active-beam interference level. It should bealso mentioned that the first receiver may select more than one firstbeam directions for data transmission in a parallel transmissionfashion. It is desirable for those skilled in the art to appreciate andconceive modification, or change to the present disclosure in differentsystem configurations or application scenario, with the teaching andsuggestion in this disclosure.

In a further embodiment of the present invention, if there is a firstbeam direction other than the first active beam direction having beenselected in the first communication link, the first receiver may informthe first transmitter with the selected first beam direction. Theinformation could be integrated with the negative acknowledgment (NACK)transmission or transmitted as a separate Radio Resource Control (RRC)or a Media Access Control (MAC) signaling (e.g., MAC control element(CE) signaling). Preferably, it could also include the time/frequencyposition that the transmitter should start the data transmission.Therefore, for the next transmission, the active beam direction shouldbe the selected beam direction, and the first receiver may receive datafrom the first transmitter in the selected first beam direction in thefirst communication link. Alternatively or additionally, in response toa first beam direction in the first communication link is selected, thefirst receiver may send a signaling to the second transmitter of thesecond communication link, and the signaling indicates that the secondtransmitter is not required to suspend transmitting to the secondreceiver in the second communication link in order to eliminate ormitigate its interference to the first link. Compared with the legacyLAT mechanism, where the interfered first transmitter may simply sendthe second transmitter a singling to suspend the transmission in thesecond communication link, the spectrum efficiency of the LAT systems inthe embodiments of the present invention is higher due to utilization ofthe spatial freedom in a communication channel. For example, thesignaling may indicate that the second transmitter is not required toselect another second beam direction in the second communication link.For another example, the signaling may indicate that the secondtransmitter to continue transmitting (if any data to be transmitted inthe second communication link) in its current active beam direction.Alternatively or additionally, information field of the signaling may benull, which implicitly indicates that the second transmitter is notrequired to suspend its transmission or the second transmitter is notrequired to select a new second beam direction or the second transmittercontinues to use its current active beam direction for furthertransmission (if any).

In a still further embodiment of the present invention, if the firstactive beam direction is selected in the first communication, the firstreceiver may inform the first transmitter to continue transmitting datain the first active beam direction for the next transmission in thefirst communication link. Alternatively or additionally, the firstreceiver may send a beam direction selection signaling to the secondtransmitter of the second communication link, and the beam directionselection signaling indicates that the second transmitter to select asecond beam direction from the second set of beam directions in thesecond communication link. In such cases, as no new first beam directionis successfully selected, the first receiver is not capable of solvingthe interference through its own first beam direction switching asdiscussed above, therefore, the first receiver may send the beamdirection selection signaling to the second transmitter in the secondcommunication link, indicating the second interfering transmitter toperform a second beam direction selection so as to lower theinterference from the second transmitter to the first receiver. It isdesirable that the beam direction selection signaling may include usefulinformation to help the second communication link select a correctsecond beam direction with acceptable interference or without anyinterference, and such useful information may be a position of the firstreceiver, for example.

In the present disclosure, the receiver may be a communication devicealso known as mobile terminal, wireless terminal and/or User Equipment(UE), which is enabled to communicate wirelessly with a transmitter in awireless communication network, sometimes also referred to as a cellularradio system. For instance, a communication device may be, but is notlimited to, mobile phone, smart phone, sensor device, meter, vehicle,household appliance, medical appliance, media player, camera, or anytype of consumer electronic, for instance, but not limited to,television, radio, lighting arrangement, tablet computer, laptop, orPersonal Computer (PC). The communication device may be a portable,pocket-storable, hand-held, computer-comprised, or vehicle-mountedmobile device, enabled to communicate voice and/or data, via a wirelessor wired connection.

Typically, in the present disclosure, the transmitter may be an accessnode in a wireless network, which may serve or cover one or severalcells of the wireless communication system. That is, the transmitterprovides radio coverage in the cell(s) and communicates over an airinterface with communication devices operating on radio frequencieswithin its range. The transmitter in some wireless communication systemsmay be also referred to as “eNB”, “eNodeB”, “NodeB”, “B node” or “gNB”for example in cellular communication systems or as “access point (AP)”in Wi-Fi or WLAN systems, depending on the technology and terminologyused. In the present disclosure, the transmitter may also be referred toas a Base Station (BS). The transmitter may be of different classes suchas e.g. macro eNodeB, home eNodeB or pico base station, or relay node inheterogeneous or homogeneous wireless networks, based on transmissionpower and thereby also cell size. It can be understood that in theuplink transmission scenarios, the first receiver may be an access node,such as a BS, while the first transmitter may be a communication device,such as a UE for example, and the methods in connection with theembodiments of FIG. 1 is still applicable in such uplink scenarios.

FIG. 3 is an exemplary flow diagram of a step of the method of FIG. 1according to one or more embodiments of the invention. As illustratedabove, the first receiver in step 130 may select a first beam directionfrom the first set of beam directions in response to determining thecommunication quality satisfying the predefined criterion. This step maybe explained in more detail with the aid of FIG. 3, which is a flowchart of a number of sub steps.

In sub step 310, the first receiver measures an interference from thesecond communication link in each of the first set of beam directions.For example, it is assumed that the active beam direction is TX 1 and RX1 beam direction, as shown in FIG. 2. Then, the first receiver maymeasure the interference energy or power in RX 2 and RX 3 beamdirection, respectively. If the interference measurement value in acandidate beam direction (e.g., RX 2 and RX 3) is lower than a certaininterference threshold, it can be seen as no interference. Theinterference measurement could be based on an aggregated energy or basedon certain reference signals from the second transmitter.

Alternatively, in some of the above mentioned embodiments in which thesub step 1230 is involved, the sub step 310 can be combined with the substep 1230 into one sub step: measuring interference from the secondcommunication link in the set of beam directions of the firstcommunication link.

In sub step 320, the first receiver may select a first beam directionwith an interference measurement value being lower than an interferencethreshold, or select with the lowest interference measurement valueamong the interference measurement values, and the selected first beamdirection is used for further transmissions in the first communicationlink.

It should be mentioned that in most circumstances the selected firstbeam direction is other than the first active beam direction. There isalso possibility that the interference measurement value of the firstactive beam direction is the lowest among the interference measurementvalues of each beam direction of the first set of beam direction. Inthis case, the first beam direction would be selected as the firstactive beam direction, or the beam direction with the second bestinterference measurement value would be selected as the first activebeam direction, but either of these selection would trigger a beamdirection selection signalling to the second transmitter, as illustratedin some of the above mentioned embodiments.

FIG. 4 illustrates an exemplary flow diagram for a method in a secondtransmitter in a second communication link in a wireless networkaccording to one or more embodiments of the invention. As discussedabove, the second communication link shares a common band in a wirelessnetwork with the first communication link between the first transmitterand the first receiver. There is a second set of beam directions in thesecond communication link, and the second transmitter and receiver inthe second communication link is working in a second active beamdirection.

In step 410, the second transmitter receives a beam direction selectionsignaling from the first receiver, and the beam direction selectionsignaling indicates the second transmitter to select a second beamdirection other than the second active beam direction from the secondset of beam directions. If the second transmitter receives the beamdirection selection signaling, it means the first communication link,i.e., a victim link is not capable of solving the interference from thesecond transmitter by itself, and the first receiver of the firstcommunication link may send this beam direction selection signaling toinitiate a coordinated processing in the interfering second transmitterof the second communication link, i.e., an aggressor link.

In step 420, the second transmitter selects a second beam directionother than the second active beam direction from the second set of beamdirections in the second communication link. It is desirable that theselection of the second beam direction from the second set of beamdirections may be performed in different ways or a combination thereof.In one embodiment of the invention, in step 4210, the second transmittermay select the second beam directions based on a space departure of eachof second set of beam directions with respect to the second active beamdirection. For example, the second beam direction other than the secondactive beam direction may be chosen as one with the largest spacedeparture of beam direction with respect to the current second activebeam direction, which may lead to a lower interference due to thelargest spatial departure with respect to the current interfering secondactive beam direction.

In another embodiment of the invention, in step 4220, the secondtransmitter may select the second beam direction based on a geometricposition of the first receiver, and the geometric position of the firstreceiver may be conveyed in the beam direction selection signaling or inother separate signaling. For example, the second transmitter maymaintain historical interference information, which is related to asecond beam direction in the second communication link and geometricposition of a first receiver in the first communication link, whichsends the second transmitter a beam direction selection signaling orreporting it with an interference occurrence. For example, the secondtransmitter may selection the second beam direction, which has the mostpossibility to have no interference or have interference below a certainthreshold. It should be appreciated that this historical interferenceinformation may be updated periodically or based on certain updatingtriggering events. The beam direction selection could be performed basedon different metrics, such as difference distance metrics or throughheuristic or machine learning algorithms.

In still another embodiment of the invention, in step 4230, the secondtransmitter may select the second beam direction based on a mappingbetween each of the second set of beam directions and an interferencelevel. For example, the interference level may be defined as a countnumber of interference times in a certain time window, whichstatistically measures the interference severity with respect to eachsecond beam direction. The second transmitter may select the second beamdirection with the lowest interference level, for example. Alternativelyor additionally, the second transmitter may select the second beamdirection by jointly considering the signal strength, such as ReferenceSignal Receiving Power (RSRP), Reference Signal Receiving Quality(RSRQ), Received Signal Strength Indication (RSSI), Signal to NoiseRatio (SNR) in the second communication link and the interference levelas descried above. It is desirable the initial beam direction may beselected based on such statistical or historical information.

In yet still another embodiment of the invention, the second transmittermay randomly select a second beam direction other than the second activebeam direction from the second set of beam directions. It should benoted that the interference may not be actually solved after the secondtransmitter selecting a second beam direction, and in such situations,when a second beam direction in the second communication link isselected, the first receiver may try again to select another first beamdirection to further mitigate the interference. Therefore, the beamdirection selection may be performed in an iterative fashion between thefirst communication link and the second communication link, as apreferable but not limiting embodiment of the invention for example. Theperson skilled in the art may conceive or appreciate any modification orvariation to the methods described above, without departing the spiritand scope of the disclosure.

In a further embodiment of the invention, the second transmitter mayinform the second receiver with the selected second beam direction andit will transmit further data to the second receiver in the selectedsecond beam direction in the second communication link. In a stillfurther embodiment of the invention, the second transmitter may suspendtransmitting data to the second receiver in the second communicationlink for a preset period, in response to receiving the beam directionselection signaling from the first receiver for a preset number oftimes. In a still further embodiment of the invention, the secondtransmitter may suspend transmitting data to the second receiver in thesecond communication link for a preset period, in response to receivingan explicit signaling, which indicates the second transmitter to suspendits transmission, i.e., not to perform a further beam directionselection. In such situations, the interference cannot be solved incertain times of attempts, which means the second transmitter shouldsuspend its transmission in order to eliminate the interference to thefirst communication link, for example. The present number of times couldbe selected or updated by the network side adapted to differentapplication scenarios.

FIG. 5 illustrates an exemplary flow diagram for a process of a firsttransmitter and a first receiver in a first communication link in awireless network according to one or more embodiments of the invention.In step 510, the first transmitter transmits data in a first active beamdirection to the first receiver in the first communication link, withoutlistening to the shared channel first. The transmission may be sufferedfrom the presence of interference from the second communication link. Instep 520, the first receiver determines the communication quality. Asdiscussed above, the communication quality may be taken in any form ofappropriate measures, which could be employed to describe the quality ofthe equivalent communication channel by taking the beamforming effect inthe first communication link into consideration. In step 525, the firstreceiver determines whether the communication quality satisfies apredefined criterion or not. If the communication quality satisfies thepredefined criterion, it means the quality of the equivalent channel isdeteriorated by the interference from the second communication link to acertain extent. Therefore, the first receiver in step 530 may select afirst beam direction in order to alleviate the interference byexploiting a spatial freedom. In step 535, it will be determined whetherthere is a first beam direction other than current active beam directionselected for beam direction switching. If there is a first beam newlyselected, the first receiver may inform the first transmitter with thenewly selected first beam direction in step 540 and the firsttransmitter may switch to the newly selected first direction for furtherdata transmission in step 550. In an optional step 560, the firstreceiver may send a signaling to the second transmitter, which indicatesthat the second transmitter is not required to suspend its transmission.If it is determined that the selected first beam direction selection isthe first active beam direction in step 535, as a preferable embodiment,the first receiver may inform the first transmitter to continuetransmission in the current first active beam direction in step 570, andit will also send the second transmitter a beam direction selectionsignaling in step 580 to instruct the second transmitter to perform asecond beam direction selection in the second communication link, inorder to further reduce the interference. For simplicity, theillustrated process is shown and described as a series of steps.However, the process may not be limited by the order of the stepsbecause, in some embodiments, the steps may occur in different ordersthan shown and described. Moreover, fewer than all the illustrated stepsmay be required to implement an example embodiment of the invention. Forexample, the first transmitter may either perform a beam switching inthe first communication link, or directly send a beam directionselection signaling to the second transmitter, causing the secondtransmitter to switch a second beam direction to lower the interference.

FIG. 6 illustrates an exemplary flow diagram for a process between asecond transmitter and a second receiver in a second communication linkin a wireless network according to one or more embodiments of theinvention. In step 610, the second transmitter may receive a beamdirection selection signaling from the first receiver in the firstcommunication link. In step 615, the second transmitter may determinewhether the beam direction selection signaling is received for a presetnumber of times. If the beam direction signaling has not been receivedfor the preset number of times, it means that second communication linkmay select a second beam direction other than the second active beamdirection in order to reduce the interference to the first communicationlink, which is shown in step 620. In such step 620, the secondtransmitter selects a second beam direction other than its active beamdirection for data transmission so as to reduce the interference to thefirst receiver. Then, the second transmitter may transmit data on thenewly selected second beam direction in step 630, and the secondreceiver may also inform the second receiver with the newly selectedbeam direction in step 640, which will cause the second receiver toswitch to the newly selected beam direction for data receiving in step650. If the beam direction selection signaling has been received for thepreset number of times in step 615, which means the interference may notbe solved via beam switching in the second communication link, and thusthe second transmitter may suspend its transmission in step 660, therebyeliminating the interference to the first communication link.

For simplicity of explanation, the methodology described in conjunctionwith FIGS. 1-6 is depicted and described as a series of acts. It is tobe understood and appreciated that aspects of the subject matterdescribed herein are not limited by the acts illustrated and/or by theorder of acts. In one embodiment, the acts occur in an order asdescribed above. In other embodiments, however, two or more of the actsmay occur in parallel or in another order. In other embodiments, one ormore of the actions may occur with other acts not presented anddescribed herein. Furthermore, not all illustrated acts may be requiredto implement the methodology in accordance with aspects of the subjectmatter described herein. In addition, those skilled in the art willunderstand and appreciate that the methodology could alternatively berepresented as a series of interrelated states via a state diagram or asevents.

FIG. 7 schematically shows a block diagram of a first receiver accordingto one or more embodiments of the invention. The first receiver 700 maybe an access node or a communication device, depending on the firsttransmission in the first communication link is an uplink transmissionor a downlink transmission. It may for example correspond to the firstreceiver described in connection with any one of FIGS. 1, 3 and 5. Thefirst receiver 700 comprises a memory 710 storing computerprocessor-executable instructions and a processing system 720 configuredto execute the instructions performing the steps of the methodillustrated in any one of FIGS. 1, 3 and 5. For example, the processingsystem 720 which includes one or more microprocessor ormicrocontrollers, as well as other digital hardware, which may includeDigital Signal Processors (DSP), special-purpose digital logic, and thelike. The processors may be configured to execute program code stored inmemory. Instructions stored in memory includes program codes forexecuting one or more telecommunications and/or data communicationsprotocols as well as program codes for carrying out one or more of thetechniques described herein, in several embodiments. For example, thememory 710 may include a Read Only Memory (ROM), e.g., a flash ROM, aRandom Access Memory (RAM), e.g., a Dynamic RAM (DRAM) or Static RAM(SRAM), a mass storage, e.g., a hard disk or solid state disk, or thelike. The memory 710 includes suitably configured program code to beexecuted by the processing system so as to implement the above-describedfunctionalities of the first receiver. In particular, the memory mayinclude various program code modules for causing the first receiver toperform processes as described above, e.g., corresponding to the methodsteps of any one of FIGS. 1, 3 and 5. The first receiver may alsocomprise at least one interface (not shown) for communicating with thewireless device or access node, e.g. a wireless interface, and/or forcommunicating with the neighboring communication device or access node,e.g. a wired or wireless interface. The interface could be coupled tothe processing system. Information and data as described above inconnection with the methods may be sent via the interface.

FIG. 8 schematically shows a block diagram of a second transmitteraccording to one or more embodiments of the present invention. Thesecond transmitter 800 may be an access node or a communication device,depending on the second transmission in the second communication link isan uplink transmission or a downlink transmission. It may for examplecorrespond to the second transmitter described in connection with anyone of FIGS. 4 and 6. The second transmitter 800 comprises a memory 810storing computer processor-executable instructions and a processingsystem 820 configured to execute the instructions performing the stepsof the method illustrated in any one of FIGS. 4 and 6. For example, theprocessing system 820 which includes one or more microprocessor ormicrocontrollers, as well as other digital hardware, which may includeDSP, special-purpose digital logic, and the like. The processors may beconfigured to execute program code stored in memory. Instructions storedin memory includes program codes for executing one or moretelecommunications and/or data communications protocols as well asprogram codes for carrying out one or more of the techniques describedherein, in several embodiments. For example, the memory 810 may includea ROM, e.g., a flash ROM, a RAM, e.g., a DRAM or SRAM, a mass storage,e.g., a hard disk or solid state disk, or the like. The memory 810includes suitably configured program code to be executed by theprocessing system so as to implement the above-described functionalitiesof the second transmitter. In particular, the memory may include variousprogram code modules for causing the second transmitter to performprocesses as described above, e.g., corresponding to the method steps ofany one of FIGS. 4 and 6. The second transmitter may also comprise atleast one interface (not shown) for communicating with the wirelessdevice or access node, e.g. a wireless interface, and/or forcommunicating with the neighboring communication device or access node,e.g. a wired or wireless interface. The interface could be coupled tothe processing system. Information and data as described above inconnection with the methods may be sent via the interface.

The present disclosure may also be embodied in the computer programproduct which comprises all features capable of implementing the methodas depicted herein and may implement the method when loaded to thecomputer system. A set of software modules may correspond to a set ofrespective steps or actions in any method described in conjunction withFIGS. 1, 3-6, and it is appreciated for the person skilled in the artthat the aforementioned modules could be implemented via ProgrammableLogic Device (PLD), Field Programmable Gate Array (FPGA), ApplicationSpecific Integrated Circuit (ASIC), and other implement mechanisms assoftware products, application specific firmware, hardware products anda combination thereof.

In general, the various exemplary embodiments may be implemented inhardware or special purpose circuits, software, logical or anycombination thereof. For example, some aspects may be implemented inhardware, while other aspects may be implemented in firmware or softwarewhich may be executed by a controller, microprocessor or other computingdevice, although the disclosure is not limited thereto. While variousaspects of the exemplary embodiments of this disclosure may beillustrated and described as block and signaling diagrams, it is wellunderstood that these blocks, apparatus, systems, techniques or methodsdescribed herein may be implemented in, as non-limiting examples,hardware, software, firmware, special purpose circuits or logical,general purpose hardware or controller or other computing devices, orsome combination thereof.

The present disclosure has been specifically illustrated and explainedwith reference to the preferred embodiments. The skilled in the artshould understand various changes thereto in form and details may bemade without departing from the spirit and scope of the presentdisclosure.

1. A method for a first receiver receiving data from a first transmitterin a first communication link, the first communication link sharing acommunication channel with a second communication link between a secondtransmitter and a second receiver in a wireless network, the firstcommunication link corresponding to a first set of beam directions, themethod comprising: receiving data from the first transmitter in a firstactive beam direction in the first communication link; determiningwhether a communication quality satisfies a predefined criterion, inpresence of interference from the second communication link between thesecond transmitter and the second receiver; and selecting a first beamdirection from the first set of beam directions in response todetermining the communication quality satisfying the predefinedcriterion.
 2. The method according to claim 1, wherein the determiningwhether a communication quality satisfies a predefined criterioncomprising: decoding the data received from the first transmitter in thefirst communication link; and determining whether the data issuccessfully decoded; wherein the selecting a first beam direction fromthe first set of beam directions comprising: selecting a first beamdirection from the first set of beam directions in response todetermining the data is not successfully decoded.
 3. The methodaccording to claim 1, wherein the determining whether a communicationquality satisfies a predefined criterion comprising: measuring aninterference from the second communication link in the first active beamdirection; and determining whether the interference is higher than apredefined active-beam interference level; wherein the selecting a firstbeam direction from the first set of beam directions comprising:selecting a first beam direction from the first set of beam directionsin response to determining the interference level being higher than thepredefined active-beam interference level.
 4. The method according toclaim 1, wherein the selecting a first beam direction from the first setof beam directions comprising: measuring an interference from the secondcommunication link in each of the first set of beam directions; andselecting a first beam direction with an interference measurement valuebeing lower than an interference threshold.
 5. The method according toclaim 1, wherein the method further comprising: in response to a firstbeam direction other than the first active beam direction having beenselected, informing the first transmitter with the selected first beamdirection; and receiving data from the first transmitter in the selectedfirst beam direction in the first communication link.
 6. The methodaccording to claim 1, wherein the method further comprising: in responseto a first beam direction other than the first active beam directionhaving been selected, sending a signaling to the second transmitter ofthe second communication link, wherein the signaling indicating that thesecond transmitter is not required to suspend transmitting to the secondreceiver in the second communication link.
 7. The method according toclaim 1, wherein the second communication link corresponding to a secondset of beam directions and the method further comprising: in response tothe selected first beam direction being the first active beam direction,informing the first transmitter to continue transmitting data in thefirst active beam direction in the first communication link.
 8. Themethod according to claim 1, wherein the second communication linkcorresponding to a second set of beam directions and the method furthercomprising: in response to the selected first beam direction being thefirst active beam direction, sending a beam direction selectionsignaling to the second transmitter of the second communication link,wherein the beam direction selection signaling indicating the secondtransmitter to select a second beam direction other than a second activebeam direction from the second set of beam directions in the secondcommunication link.
 9. A method for a second transmitter transmittingdata to a second receiver in a second communication link, the secondcommunication link sharing a communication channel with a firstcommunication link between a first transmitter and a first receiver in awireless network, the second communication link corresponding to asecond set of beam directions, the method comprising: receiving a beamdirection selection signaling from the first receiver, wherein the beamdirection selection signaling indicating the second transmitter toselect a second beam direction from the second set of beam directions;and selecting a second beam direction other than a second active beamdirection from the second set of beam directions in the secondcommunication link.
 10. The method according to claim 9, wherein theselecting the second beam direction from the second set of beamdirections comprising: selecting the second beam direction based on aspace departure of each of second set of beam directions with respect tothe second active beam direction.
 11. The method according to claim 9,wherein the selecting the second beam direction from the second set ofbeam directions further comprising: selecting the second beam directionbased on a geometric position of the first receiver, wherein thegeometric position of the first receiver is conveyed in the beamdirection selection signaling.
 12. The method according to claim 9,wherein the selecting the second beam direction from the second set ofbeam directions further comprising: selecting the second beam directionbased on a mapping between each of the second set of beam directions andan interference level.
 13. The method according to claim 9 wherein themethod further comprising: informing the second receiver with theselected second beam direction; and transmitting data to the secondreceiver in the selected second beam direction in the secondcommunication link.
 14. The method according to claim 9, wherein themethod further comprising: in response to receiving the beam directionselection signaling from the first receiver for a preset number oftimes, suspending transmitting data to the second receiver in the secondcommunication link for a preset period.
 15. A first receiver in awireless network, the first receiver comprising: a memory storingprocessor-executable instructions, and a processing system comprisingone or more processors configured to execute the processor-executableinstructions to: receive data from a first transmitter in a first activebeam direction in a first communication link; determine whether acommunication quality satisfies a predefined criterion in presence ofinterference from the second communication link between the secondtransmitter and the second receiver; and select a first beam directionfrom the first set of beam directions in response to determining thecommunication quality satisfying the predefined criterion.
 16. The firstreceiver according to claim 15, wherein to determine whether acommunication quality satisfies a predefined criterion comprises:decoding the data received from the first transmitter in the firstcommunication link; and determining whether the data is successfullydecoded, wherein to select a first beam direction from the first set ofbeam directions comprises selecting a first beam direction from thefirst set of beam directions in response to determining the data is notsuccessfully decoded.
 17. The first receiver according to claim 15,wherein to determine whether a communication quality satisfies apredefined criterion comprises: measuring an interference from thesecond communication link in the first active beam direction; anddetermining whether the interference is higher than a predefinedactive-beam interference level; wherein to select a first beam directionfrom the first set of beam directions comprises selecting a first beamdirection from the first set of beam directions in response todetermining the interference level being higher than the predefinedactive-beam interference level.
 18. A second transmitter in a wirelessnetwork, the second transmitter comprising: a memory storingprocessor-executable instructions, and a processing system comprisingone or more processors configured to execute the processor-executableinstructions to: receive a beam direction selection signaling from afirst receiver, wherein the beam direction selection signalingindicating a second transmitter to select a second beam direction from asecond set of beam directions; and select a second beam direction otherthan a second active beam direction from the second set of beamdirections.
 19. The second transmitter according to claim 18, wherein toselect the second beam direction from the second set of beam directionscomprises: selecting the second beam direction based on a spacedeparture of each of the second set of beam directions with respect tothe second active beam direction.
 20. The second transmitter accordingto claim 18, wherein to select the second beam direction from the secondset of beam directions comprises: selecting the second beam directionbased on a geometric position of the first receiver, wherein thegeometric position of the first receiver is conveyed in the beamdirection selection signaling.